We just learned that Dick Van Dykecancelled his appearance at Manhattan's 92nd Street Y because of a "yet-to-be diagnosed neurological disorder," and now, even though tests revealed that he's completely healthy, the 87-year-old comedian still feels sick.

Dick's spokesman, Bob Palmer revealed that the actor was undergoing tests for "cranial throbbing," but since doctors can't find a diagnosis, Van Dyke has to deal with his unfortunate pain until they know what exactly is wrong.

Palmer said that the star is fine, but his "fatigue factor has become acute."

The Diagnosis Murder star is not allowed to fly at the moment, so he's been kicking back in his Malibu home until further notice.

"My metabolism actually changed like crazy this year. I have Hashimoto's disease. It's a thyroid disease, and it's now been two years since taking the medication for it, so for the VS show I didn't want to lose any more weight, I just want to have muscles in the right place, and if my butt can get a little perkier, then that's good."